1. Field of the Invention
The present invention relates to hole plugs and in particular to plugs for holes in the core barrel of the internals of a nuclear reactor.
2. General Background
In certain nuclear reactors such as the PGE Trojan Reactor the core barrel is provided with holes in accordance with the design thereof. Holes in the core may be plugged when it is desired to modify the design. To limit exposure to the radioactivity of the core, it is preferable to utilize plugs which may be remotely installed and removed.
Several plugs exist in the known art.
U.S. Pat. No. 4,465,039 entitled "Engine Block Heater With Expansion Yoke" teaches an engine block heater adapted for insertion in the block of an engine. A pressure bar threaded onto a screw in the plug has winged members hingedly mounted thereon for contacting the inner face of the block to retain the plug in position.
U.S. Pat. No. 4,175,229 entitled "Engine Block Heater" teaches an engine jacket heater utilizing winged members and a clamp engaged with a screw for spreading the wing members into engagement with the engine jacket.
U.S. Pat. No. 4,485,771 entitled "Engine Block Heater Having Flexible Clamping Member" teaches a flexible bar and rigid member on a screw of the assembly for engaging the engine block.
U.S. Pat. No. 135,822 and 969,881 teach locking caps with pivotally mounted locking members which bear against the walls of the bore being covered.
U.S. Pat. Nos. 4,461,597 entitled "Valve Box Cover", 4,242,564 entitled "Frost Plug Immersion Heater and Improved Clamping Structure", 4,480,604 entitled "Engine Block Heater", and 3,010,694 entitled "Conduit Plug and Coupling Assembly" teach covers and plugs similar to the above and are representative of the art.
The above known art does not solve the problem of providing a plug capable of being remotely installed and removed which can withstand the severe operating conditions encountered in a nuclear reactor.